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ISAAC e. TATE, or NEW LoNDe-N, coNNEG.TIGU'T.

Leners Patent No. 78,157, dated May 19, 186s.

IMPROVEMENT IN BRAGS FOB. BITS.

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TO ALL WHOM IT'MAY CONGERN: 1

Be it known that I, ISAAC C. Tarn, 'of New London, in the county of New London, and State of Connecticut, have invented a new and improved Bit-Stock; and I do hereby declare that the following is a full, clear, and exact description thereof whichwill enable others skilled. in the art to make and use the same, reference being had to the accompanying drawings, forming part-of this speciiication, in whichl `Figure 1 represents a side view of my improved btsteck.

Figure 2 is an inverted planview of the same., g

Figure 8 is a detail vertical sectional view of the saine, the pinne of section being indicated by the line x x, g. l. t i

Similar letters of reference indicate corresponding parts.

This invention relates to a new manner of' arranging a bit-stock, which will not onlybe adapted to hold any-sized shank,ibuizlwhich is also adapted to gripe both the square shank and the round bedywof a bit-stock,

The invention consists in securing te each arm `of a brace which has a slotted socket, a spring-jaw, which is to clamp the round portion of the'bit, and on which the shoulder for sustaining'the' head or lshank of the bit l is formed. Y

These jaws are made of cast steel, somthat the shoulders cannot be easily wernout. It will be seen that when the shank of the bit is, by means of a thumb-screw, xed in the Vtwo arms of the brace, the aforesaid jaws will t around and clamp the round part et' the shank.

A represents the arm of a brace. The same isl slotted, so that its socket, B, will be divided into two parts, as shown, which may be'forced together by a thumb-screw, a, if desired. v,One of the two 'armsB may be hinged or otherwise connected with the arm A, or it may be cast in one piece with the same, as may be desired.

On the inside of each arm B is a V-shaped recess, b, extending from top to bottom of the socket, and broader at the bottom than at the top. No shoulder or stop is formed in these grooves, which nre to hold the header shank of the hit, as is clearly shown in'iig. 3.

To the outside of each arm B is secured, by means of aV screw. or rivet, e, a spring, C, which lies on the side of thevarm B, as shown.

Atthe lower end ef each spring C, below the bottom of the socket B, is formed zi/jaw, al. These jaws are so formed that when they arc closed together around hole will be formed between them, which gradually enlarges at the top, (as in fig. 3,) so as to form a hold for the roundpart of the bit, and a support for the shankV of the same.

When the'bit is to he inserted, the arms B B are spread apart, the springs C C following the same, The

' head o f the bit is then inserted into the groeve and the arms are then closed around it by the use ofthe screw a; thereby the jaws l 'are brought together, and will, by the springs C, be firmly clamped around the roundf part of the bit, as is clearly shown in iig. 3. Y Y

It will be seen that the springs C will force the jaws d against the bit, nghatevcr the size of the head of the bit may be; and as therjaws d arc formed of cast or other steel, the shoulderforme'd in them for the support of the head-of the bit will not wear out so quick and-se easy as @c shoulder generally formed in the socket, which is made of malleable iron.4

I disclaim the use of a slotted brace socket, whether the parts are hinged together er otherwise connected. I am aware of thc patent granted te N. Spoiord, and dated November l, 1859; butasthis forms no part ef my invention, I do not therefore claim it; but

I de claim, and desireto secure by Letters Patent V The combination of the spring-jaws C with the socket of the bit-stock, substantially as herein shown and described.

I. C. TATE.

Witnesses:

- WM. F. McNAMAnA, ALEX, F. Itonnnrs. 

